protected bool IsOutgoingEmail(IPersistentEmail email) { return IsInternalSender(email) && HasExternalRecipients(email); }
protected bool IsIncomingEmail(IPersistentEmail email) { return !IsInternalSender(email); }
protected bool IsInternalSender(IPersistentEmail email) { return IsInternalEmailAddress(email.Sender); }
protected bool HasExternalRecipients(IPersistentEmail email) { return email.Recipients.Any(recipient => !IsInternalEmailAddress(recipient)); }